You did a very silly, idiotic thing 4 years ago. I cannot stand drink drivers - I think it's a lunatic act which is as selfish as it is pathetic. However, that said, you have been judged bu a Court and you have got your fine and your ban. I don't see any reason why you should be further punished by potentially losing your job. Therefore I would stay quiet, put it out of your mind and get on with your life. I'm all for honesty, clean conscience and all that - but a clean conscience does not pay the bills and honesty is poor company on your way down to the dole office. In terms of HR finding out - you work for an investment bank. Apart from the inordinate proprotion of criminals ALREADY working for them, their HR function will be very similar to other organizations - i.e. not necessarily Sherlock Holmes. However their lack of investigative capabilities will be more than compensated by their bureaurocratic management of the whole situation if you DO tell them. There will be reviews of your performance, they may fire you, they may demote you - at the very least they will make you feel like your conviction was for murder, not drink driving.So learn the handbook - keep your mouth shut - chill out and live your life... There will be a thousand reasons why your employer will get rid of you in your career - don't give them 1 more....